Make command in authorized keys a template (#16003)

Fix #15595
Replaces #15978

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
This commit is contained in:
zeripath 2021-06-15 02:15:12 +01:00 committed by GitHub
parent ebf253b841
commit 95352e6bd5
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
3 changed files with 60 additions and 43 deletions

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@ -270,6 +270,7 @@ The following configuration set `Content-Type: application/vnd.android.package-a
- `SSH_AUTHORIZED_PRINCIPALS_ALLOW`: **off** or **username, email**: \[off, username, email, anything\]: Specify the principals values that users are allowed to use as principal. When set to `anything` no checks are done on the principal string. When set to `off` authorized principal are not allowed to be set.
- `SSH_CREATE_AUTHORIZED_PRINCIPALS_FILE`: **false/true**: Gitea will create a authorized_principals file by default when it is not using the internal ssh server and `SSH_AUTHORIZED_PRINCIPALS_ALLOW` is not `off`.
- `SSH_AUTHORIZED_PRINCIPALS_BACKUP`: **false/true**: Enable SSH Authorized Principals Backup when rewriting all keys, default is true if `SSH_AUTHORIZED_PRINCIPALS_ALLOW` is not `off`.
- `SSH_AUTHORIZED_KEYS_COMMAND_TEMPLATE`: **{{.AppPath}} --config={{.CustomConf}} serv key-{{.Key.ID}}**: Set the template for the command to passed on authorized keys. Possible keys are: AppPath, AppWorkPath, CustomConf, CustomPath, Key - where Key is a `models.PublicKey` and the others are strings which are shellquoted.
- `SSH_SERVER_CIPHERS`: **aes128-ctr, aes192-ctr, aes256-ctr, aes128-gcm@openssh.com, arcfour256, arcfour128**: For the built-in SSH server, choose the ciphers to support for SSH connections, for system SSH this setting has no effect.
- `SSH_SERVER_KEY_EXCHANGES`: **diffie-hellman-group1-sha1, diffie-hellman-group14-sha1, ecdh-sha2-nistp256, ecdh-sha2-nistp384, ecdh-sha2-nistp521, curve25519-sha256@libssh.org**: For the built-in SSH server, choose the key exchange algorithms to support for SSH connections, for system SSH this setting has no effect.
- `SSH_SERVER_MACS`: **hmac-sha2-256-etm@openssh.com, hmac-sha2-256, hmac-sha1, hmac-sha1-96**: For the built-in SSH server, choose the MACs to support for SSH connections, for system SSH this setting has no effect

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@ -38,7 +38,6 @@ import (
const (
tplCommentPrefix = `# gitea public key`
tplCommand = "%s --config=%s serv key-%d"
tplPublicKey = tplCommentPrefix + "\n" + `command=%s,no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty %s` + "\n"
authorizedPrincipalsFile = "authorized_principals"
@ -88,7 +87,16 @@ func (key *PublicKey) OmitEmail() string {
// AuthorizedString returns formatted public key string for authorized_keys file.
func (key *PublicKey) AuthorizedString() string {
return fmt.Sprintf(tplPublicKey, util.ShellEscape(fmt.Sprintf(tplCommand, util.ShellEscape(setting.AppPath), util.ShellEscape(setting.CustomConf), key.ID)), key.Content)
sb := &strings.Builder{}
_ = setting.SSH.AuthorizedKeysCommandTemplateTemplate.Execute(sb, map[string]interface{}{
"AppPath": util.ShellEscape(setting.AppPath),
"AppWorkPath": util.ShellEscape(setting.AppWorkPath),
"CustomConf": util.ShellEscape(setting.CustomConf),
"CustomPath": util.ShellEscape(setting.CustomPath),
"Key": key,
})
return fmt.Sprintf(tplPublicKey, util.ShellEscape(sb.String()), key.Content)
}
func extractTypeFromBase64Key(key string) (string, error) {

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@ -20,6 +20,7 @@ import (
"runtime"
"strconv"
"strings"
"text/template"
"time"
"code.gitea.io/gitea/modules/generate"
@ -123,48 +124,51 @@ var (
AbsoluteAssetURL string
SSH = struct {
Disabled bool `ini:"DISABLE_SSH"`
StartBuiltinServer bool `ini:"START_SSH_SERVER"`
BuiltinServerUser string `ini:"BUILTIN_SSH_SERVER_USER"`
Domain string `ini:"SSH_DOMAIN"`
Port int `ini:"SSH_PORT"`
ListenHost string `ini:"SSH_LISTEN_HOST"`
ListenPort int `ini:"SSH_LISTEN_PORT"`
RootPath string `ini:"SSH_ROOT_PATH"`
ServerCiphers []string `ini:"SSH_SERVER_CIPHERS"`
ServerKeyExchanges []string `ini:"SSH_SERVER_KEY_EXCHANGES"`
ServerMACs []string `ini:"SSH_SERVER_MACS"`
ServerHostKeys []string `ini:"SSH_SERVER_HOST_KEYS"`
KeyTestPath string `ini:"SSH_KEY_TEST_PATH"`
KeygenPath string `ini:"SSH_KEYGEN_PATH"`
AuthorizedKeysBackup bool `ini:"SSH_AUTHORIZED_KEYS_BACKUP"`
AuthorizedPrincipalsBackup bool `ini:"SSH_AUTHORIZED_PRINCIPALS_BACKUP"`
MinimumKeySizeCheck bool `ini:"-"`
MinimumKeySizes map[string]int `ini:"-"`
CreateAuthorizedKeysFile bool `ini:"SSH_CREATE_AUTHORIZED_KEYS_FILE"`
CreateAuthorizedPrincipalsFile bool `ini:"SSH_CREATE_AUTHORIZED_PRINCIPALS_FILE"`
ExposeAnonymous bool `ini:"SSH_EXPOSE_ANONYMOUS"`
AuthorizedPrincipalsAllow []string `ini:"SSH_AUTHORIZED_PRINCIPALS_ALLOW"`
AuthorizedPrincipalsEnabled bool `ini:"-"`
TrustedUserCAKeys []string `ini:"SSH_TRUSTED_USER_CA_KEYS"`
TrustedUserCAKeysFile string `ini:"SSH_TRUSTED_USER_CA_KEYS_FILENAME"`
TrustedUserCAKeysParsed []gossh.PublicKey `ini:"-"`
PerWriteTimeout time.Duration `ini:"SSH_PER_WRITE_TIMEOUT"`
PerWritePerKbTimeout time.Duration `ini:"SSH_PER_WRITE_PER_KB_TIMEOUT"`
Disabled bool `ini:"DISABLE_SSH"`
StartBuiltinServer bool `ini:"START_SSH_SERVER"`
BuiltinServerUser string `ini:"BUILTIN_SSH_SERVER_USER"`
Domain string `ini:"SSH_DOMAIN"`
Port int `ini:"SSH_PORT"`
ListenHost string `ini:"SSH_LISTEN_HOST"`
ListenPort int `ini:"SSH_LISTEN_PORT"`
RootPath string `ini:"SSH_ROOT_PATH"`
ServerCiphers []string `ini:"SSH_SERVER_CIPHERS"`
ServerKeyExchanges []string `ini:"SSH_SERVER_KEY_EXCHANGES"`
ServerMACs []string `ini:"SSH_SERVER_MACS"`
ServerHostKeys []string `ini:"SSH_SERVER_HOST_KEYS"`
KeyTestPath string `ini:"SSH_KEY_TEST_PATH"`
KeygenPath string `ini:"SSH_KEYGEN_PATH"`
AuthorizedKeysBackup bool `ini:"SSH_AUTHORIZED_KEYS_BACKUP"`
AuthorizedPrincipalsBackup bool `ini:"SSH_AUTHORIZED_PRINCIPALS_BACKUP"`
AuthorizedKeysCommandTemplate string `ini:"SSH_AUTHORIZED_KEYS_COMMAND_TEMPLATE"`
AuthorizedKeysCommandTemplateTemplate *template.Template `ini:"-"`
MinimumKeySizeCheck bool `ini:"-"`
MinimumKeySizes map[string]int `ini:"-"`
CreateAuthorizedKeysFile bool `ini:"SSH_CREATE_AUTHORIZED_KEYS_FILE"`
CreateAuthorizedPrincipalsFile bool `ini:"SSH_CREATE_AUTHORIZED_PRINCIPALS_FILE"`
ExposeAnonymous bool `ini:"SSH_EXPOSE_ANONYMOUS"`
AuthorizedPrincipalsAllow []string `ini:"SSH_AUTHORIZED_PRINCIPALS_ALLOW"`
AuthorizedPrincipalsEnabled bool `ini:"-"`
TrustedUserCAKeys []string `ini:"SSH_TRUSTED_USER_CA_KEYS"`
TrustedUserCAKeysFile string `ini:"SSH_TRUSTED_USER_CA_KEYS_FILENAME"`
TrustedUserCAKeysParsed []gossh.PublicKey `ini:"-"`
PerWriteTimeout time.Duration `ini:"SSH_PER_WRITE_TIMEOUT"`
PerWritePerKbTimeout time.Duration `ini:"SSH_PER_WRITE_PER_KB_TIMEOUT"`
}{
Disabled: false,
StartBuiltinServer: false,
Domain: "",
Port: 22,
ServerCiphers: []string{"aes128-ctr", "aes192-ctr", "aes256-ctr", "aes128-gcm@openssh.com", "arcfour256", "arcfour128"},
ServerKeyExchanges: []string{"diffie-hellman-group1-sha1", "diffie-hellman-group14-sha1", "ecdh-sha2-nistp256", "ecdh-sha2-nistp384", "ecdh-sha2-nistp521", "curve25519-sha256@libssh.org"},
ServerMACs: []string{"hmac-sha2-256-etm@openssh.com", "hmac-sha2-256", "hmac-sha1", "hmac-sha1-96"},
KeygenPath: "ssh-keygen",
MinimumKeySizeCheck: true,
MinimumKeySizes: map[string]int{"ed25519": 256, "ed25519-sk": 256, "ecdsa": 256, "ecdsa-sk": 256, "rsa": 2048},
ServerHostKeys: []string{"ssh/gitea.rsa", "ssh/gogs.rsa"},
PerWriteTimeout: PerWriteTimeout,
PerWritePerKbTimeout: PerWritePerKbTimeout,
Disabled: false,
StartBuiltinServer: false,
Domain: "",
Port: 22,
ServerCiphers: []string{"aes128-ctr", "aes192-ctr", "aes256-ctr", "aes128-gcm@openssh.com", "arcfour256", "arcfour128"},
ServerKeyExchanges: []string{"diffie-hellman-group1-sha1", "diffie-hellman-group14-sha1", "ecdh-sha2-nistp256", "ecdh-sha2-nistp384", "ecdh-sha2-nistp521", "curve25519-sha256@libssh.org"},
ServerMACs: []string{"hmac-sha2-256-etm@openssh.com", "hmac-sha2-256", "hmac-sha1", "hmac-sha1-96"},
KeygenPath: "ssh-keygen",
MinimumKeySizeCheck: true,
MinimumKeySizes: map[string]int{"ed25519": 256, "ed25519-sk": 256, "ecdsa": 256, "ecdsa-sk": 256, "rsa": 2048},
ServerHostKeys: []string{"ssh/gitea.rsa", "ssh/gogs.rsa"},
AuthorizedKeysCommandTemplate: "{{.AppPath}} --config={{.CustomConf}} serv key-{{.Key.ID}}",
PerWriteTimeout: PerWriteTimeout,
PerWritePerKbTimeout: PerWritePerKbTimeout,
}
// Security settings
@ -785,6 +789,10 @@ func NewContext() {
}
SSH.ExposeAnonymous = sec.Key("SSH_EXPOSE_ANONYMOUS").MustBool(false)
SSH.AuthorizedKeysCommandTemplate = sec.Key("SSH_AUTHORIZED_KEYS_COMMAND_TEMPLATE").MustString(SSH.AuthorizedKeysCommandTemplate)
SSH.AuthorizedKeysCommandTemplateTemplate = template.Must(template.New("").Parse(SSH.AuthorizedKeysCommandTemplate))
SSH.PerWriteTimeout = sec.Key("SSH_PER_WRITE_TIMEOUT").MustDuration(PerWriteTimeout)
SSH.PerWritePerKbTimeout = sec.Key("SSH_PER_WRITE_PER_KB_TIMEOUT").MustDuration(PerWritePerKbTimeout)